1. Field of the Invention
The present invention relates to a breathing device for administering a liquid medicant to a patient.
2. Prior Art
Nebulizers or atomizers used with intermittent positive pressure breathing (IPPB) equipment or with the patient's own natural breathing effort have been proven effective as a delivery system for liquid medicant.
A problem with many previous nebulizers is the size and distribution of liquid particles that are produced. Large droplets of medication are trapped on the walls of the mouth or throat, and as such, never pass into the lungs. For the liquid medication to reach the smaller passages in the bronchial tubes and lungs, the size of the liquid particles must be below 5 microns. At one time, an average particle size under 5 microns was acceptable. Increasingly, however, an even smaller average particle size is being called for by the medical community with certain medications and for certain treatments. Additionally, the actual particle count delivered is of great importance.
A further problem associated with many nebulizers is that they are not directly responsive to the increase or decrease in the patient's breathing. When a patient inhales, he or she is typically inhaling at a rate from 15 to 50 liters per minute. The output of most nebulizers drops off dramatically when a patient inhales at a rate exceeding 20 liters per minute.
In the present invention, all of the air inhaled by the patient is directed past the saturated mist. As the air flow to the patient's lungs is increased, additional liquid particles are delivered to the lungs. Conversely, when the air flow to the patient's lungs is decreased, the number of liquid particles is decreased. Thus, the amount of saturated air delivered to the patient is directly responsive to the increase or decrease in the patient's breathing.
Applicant is aware of a number of prior art patents including Glenn (U.S. Pat. No. 4,007,238) and Lester (U.S. Pat. No. 4,512,341).
The Lester nebulizer is connected to a breathing apparatus to allow entry of atmospheric air. The nebulizer is connected to a "T" in the air supply line. As the patient breathes in, additional atmospheric air is drawn into the lungs. The amount of saturated air, however, does not change in response to the patient's breathing.
Applicant's prior patent (U.S. Pat. No. 4,007,238) solved the problem and provides responsiveness to the patient's breathing. A significant number of improvements, however, has been made and are included in the present invention.
An additional baffle system has been provided in the present invention which serves to further reduce the average particle size delivered. The baffling may be added as an option to the nebulizer and may be removed, if desired. The additional baffle system may take a number of configurations and is interchangeable depending on the particular medication and treatment prescribed.
Additionally, the present invention has a design which more evenly distributes the atmospheric air which passes through the chimney and mixes with the saturated mist. The ability to provide a thoroughly saturated mist is, thus, enhanced.
It is a principal object and purpose of this invention to provide a nebulizer which, with a supply of pressurized air, will produce a fine mist of liquid droplets of extremely small size.
It is further object and purpose of the present invention to provide a nebulizer with a removable baffling system to vary the size of liquid particles.